Thursday, January 10, 2013

PRP beats Placebo for Knee Arthritis

The American Journal of Sports Medicine recently published the results of another study supporting the use of Platelet Rich Plasma for arthritis. In this very well done study, two different doses of PRP were given to patients and then compared to a saline injection. One group recieved a single injection of PRP, another two PRP injections spaced 3 weeks apart and the third group a single injection of saline or sterile salt water. The third group served the placebo control.

Statistically significant improvements in pain and function were noted in the PRP groups within 2-3 weeks and lasted 6 months. The saline treated group noted worsening of symptoms. There were no significant differences between the two PRP groups with both showing improvement.

Overall, this prospective, randomized trial adds to the mounting evidence that specific forms of PRP can be helpful for patients with knee osteoarthritis. See abstract below for details.

The use of PRP for knee osteoarthritis is rapidly evolving. There are now 37 articles on PubMed discussing that specific topic. (Link to abstracts) Over the course of 2013, more presentations and papers will help clarify the role of PRP for this very common problem.

BACKGROUND:Specific growth factors have been proposed as therapeutic proteins for cartilage repair. HYPOTHESIS:Platelet-rich plasma (PRP) provides symptomatic relief in early osteoarthritis (OA) of the knee. STUDY DESIGN:Randomized controlled trial; Level of evidence, 1. METHODS:A total of 78 patients (156 knees) with bilateral OA were divided randomly into 3 groups. Group A (52 knees) received a single injection of PRP, group B (50 knees) received 2 injections of PRP 3 weeks apart, and group C (46 knees) received a single injection of normal saline. White blood cell (WBC)-filtered PRP with a platelet count 3 times that of baseline (PRP type 4B) was administered in all. All the groups were homogeneous and comparable in baseline characteristics. Clinical outcome was evaluated using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) questionnaire before treatment and at 6 weeks, 3 months, and 6 months after treatment. They were also evaluated for pain by a visual analog scale, and overall satisfaction with the procedure and complications were noted. RESULTS:Statistically significant improvement in all WOMAC parameters was noted in groups A and B within 2 to 3 weeks and lasting until the final follow-up at 6 months, with slight worsening at the 6-month follow-up. The mean WOMAC scores (pain, stiffness, physical function, and total score) for group A at baseline were 10.18, 3.12, 36.56, and 49.86, respectively, and at final follow-up were 5.00, 2.10, 20.08, and 27.18, respectively, showing significant improvement. Similar improvement was noted in group B (mean WOMAC scores at baseline: 10.62, 3.50, 39.10, and 53.20, respectively; mean WOMAC scores at final follow-up: 6.18, 1.88, 22.40, and 30.48, respectively). In group C, the mean WOMAC scores deteriorated from baseline (9.04, 2.70, 33.80, and 45.54, respectively) to final follow-up (10.87, 2.76, 39.46, and 53.09, respectively). The 3 groups were compared with each other, and no improvement was noted in group C as compared with groups A and B (P < .001). There was no difference between groups A and B, and there was no influence of age, sex, weight, or body mass index on the outcome. Knees with Ahlback grade 1 fared better than those with grade 2. Mild complications such as nausea and dizziness, which were of short duration, were observed in 6 patients (22.2%) in group A and 11 patients (44%) in group B. CONCLUSION:A single dose of WBC-filtered PRP in concentrations of 10 times the normal amount is as effective as 2 injections to alleviate symptoms in early knee OA. The results, however, deteriorate after 6 months. Both groups treated with PRP had better results than did the group injected with saline only.